1VZI

Structure of superoxide reductase bound to ferrocyanide and active site expansion upon X-ray induced photoreduction

Summary for 1VZI

• Entry DOI: 10.2210/pdb1vzi/pdb
• Related: 1VZG 1VZH
• Descriptor: DESULFOFERRODOXIN, CALCIUM ION, CHLORIDE ION, ... (5 entities in total)
• Functional Keywords: ferrocyanide, microspectrophotometry, redox states, photoreduction, dinuclear iron cluster, oxidoreductase, electron transport
• Biological source: DESULFOVIBRIO BAARSII
• Total number of polymer chains: 2
• Total formula weight: 28682.07

Authors

Adam, V.,Royant, A.,Niviere, V.,Molina-Heredia, F.P.,Bourgeois, D. (deposition date: 2004-05-19, release date: 2004-08-27, Last modification date: 2024-05-08)

Primary citation

Adam, V.,Royant, A.,Niviere, V.,Molina-Heredia, F.P.,Bourgeois, D.
Structure of superoxide reductase bound to ferrocyanide and active site expansion upon X-ray-induced photo-reduction.
Structure, 12:1729-1740, 2004

PubMed Abstract: Some sulfate-reducing and microaerophilic bacteria rely on the enzyme superoxide reductase (SOR) to eliminate the toxic superoxide anion radical (O2*-). SOR catalyses the one-electron reduction of O2*- to hydrogen peroxide at a nonheme ferrous iron center. The structures of Desulfoarculus baarsii SOR (mutant E47A) alone and in complex with ferrocyanide were solved to 1.15 and 1.7 A resolution, respectively. The latter structure, the first ever reported of a complex between ferrocyanide and a protein, reveals that this organo-metallic compound entirely plugs the SOR active site, coordinating the active iron through a bent cyano bridge. The subtle structural differences between the mixed-valence and the fully reduced SOR-ferrocyanide adducts were investigated by taking advantage of the photoelectrons induced by X-rays. The results reveal that photo-reduction from Fe(III) to Fe(II) of the iron center, a very rapid process under a powerful synchrotron beam, induces an expansion of the SOR active site.

PubMed: 15341736
DOI: 10.1016/j.str.2004.07.013

Experimental method

X-RAY DIFFRACTION (1.15 Å)